Lack of Interference of Chloramphenicol with Penicillin in Hemolytic Streptococcal Infection in Mice

Abstract

Mice infected with group A streptococci were treated with chloramphenicol and penicillin, separately and in combination. Jawetz''s observation that chloramphenicol interfered with penicillin when animals were given a single aqueous injn. of both antibiotics was confirmed. The interference was not demonstrable, however, when antibiotic blood levels were maintained for 2 or 3 days. Despite early interference, the combination caused a progressive bactericidal action which, in conjunction with phagocytosis, protected the mice as well as penicillin alone. These expts. imply that the phenomenon of antibiotic interference is seldom of clinical significance.